International photographer (Jan-Dec 1934)

Twenty-eight T h INTERNATIONAL PHOTOGRAPHER April, 1934 MOTION PICTURE SOUND RECORDING (Continued from Page 21) ear in the chart. Likewise, the maximal intensity that must be handled by a sound system is some thirty decibels less than the absolute maximal for the human ear, because the additional thirty decibels of sensitivity is necessary only for the great volume of sound produced by such things as explosions and big-gun fire. From these figures, it is evident that a sound recording and reproducing system capable of handling an intensity range in the order of seventy decibels under normal operating conditions would be entirely satisfactory. Given that intensity range and true fidelity of recording and reproduction throughout a frequency range of thirty to 10,000 cycles, or double vibrations, per second a sound system would be as perfect as human hearing would require. Until such an intensity range is obtained, however, the monitor man must be careful that he keeps the level of the speech current fed to the recording amplifiers recording amplifiers in the amplifier room, the point to within the limits of the system. This chapter concludes the series of chapters on monitoring. The next chapter will begin the discussion of the recording amplifiers in the amplified room, the point to which the speech current is fed by a transmission line after leaving the main volume control in the monitor room. MINIATURE CAMERAS AND PHOTOGRAPHY (Continued from Page 23) The telephoto lens allows individuals to be snapped at a distance, so that they can be caught unawares. The photographer can position himself at a considerable distance from his subject, adjust the lens as to diaphragm and distance settings, and then shoot the picture at the proper time. The speed lens opens up possibilities of taking photos in well lighted interiors and streets. With lenses of speed such as f :2, f:1.9 and f : 1 .5 available and fast films like the Eastman Supersensitive Panchromatic, DuPont Superior, and Agfa Superpan, exposure in well lighted interiors should present no difficulty. Users of the Leica camera now have at their disposal a unique accessory which is a great aid in candid photography. This is a Photoflash device which synchronizes with the shutter. It consists of a metal tube which fits into the clip in the top of the camera, a folding metal reflector, and connections for the camera shutter release button. A small pilot light is provided which is used to properly synchronize the flash with the shutter. Once this synchronization has been established it is not necessary to use the pilot light any further. This outfit will accommodate the three sizes of Photoflash bulbs. Another aid to candid photography of which the Leica owner can avail himself is the angle view finder. 6-A 34 FILTER TRANSMISSION GRAPHS Wratren Light Filters ioc-> 75 5 MR 20^ «1 MS 5fc 25 ju 70 2 IviOLET BLUE B-G GREEN Y-G YEL OR R-0 REP 400 440 460 SIO 550 £75 600 630 6SO 3N5 700 m «1 MS 5fc .252 /oS 1 VIOLET 1 BLUE BG GREEN Y-G YEL OR R-0 RED 400 -440 4 80 5 10 5, SO 57. 5 61 JO £0 10 6. 50 70< J 5N5 GREEN 400 440 Y-G YEL OR R-0 RED 460 510 550 575 600 630 6SO No. 7. Kl'/i 700 Data by Eastman Kodak Co. Wratten Filters. 1932 Edition. 1< 8mm . FILM DATA c o zz '£. 2 O "J UJ 01 o\ ,_, ,_, ,4. vo ^ ON r CM „. m on CM Tt 00 h-e£ */> w> E CO vc <>% V C CM CO CM CM CM co CO uj i/i rc a O UJ 2 S2! "-H *2 o2 ** S+. LLI u_ z " O (U 1— * Qf s-« 00 00 IS. 00 o vo cm co *<t CO CO CM <n 0\ < LU h-U °t ■_• O CM CM CM CM £ 2 o< mfc Q£ — =)Q V „ U!5 01 : t/> 0$ -t vo CO o CM Tl vo y O -1 — 3 a O CM CM cm m t ^t -t VO Q-O <u ■* >> X X >, X X x >» >-. >> X j^ c X — — Jl X X X .0 X X Q X X U C£ (^ Q *" o in o< o < c 0\ CD CM co VO 00 On CM ^ i>. co > CM c\) CM CM co LU N IS) < O "J *2 LO LU z< o z < > No CM \n CT\ CM m °."^ ai *~; TJ \o Ov "-• Tf vO 00 rH CO C m VO X VO in c x«> u. *"• ■_< 1-1 '-' CM CM CM co tJ in GO ^ _J C X X X X >1 X X X X >, X X E +t ^-1 JJ _ »Q — X .C jO — X u o fT\ b fa — 3 o •~J rn LO VjO 00 o CM ■■tf \o tN CM VO tT CO rn > 3 U O = CM CM CO <<J VO 00 .2% ■a <y <*) I~x m rn O on (/> ,12 n "■, c rs. fo •-, »>« ,^ l-< 00 rf «-" in CJV v: c o -J ■— ■ ^^ ■<fr un vO VO on m VO in CO c — CM co *D >» ,>> >» X X >, X X X X X — E 4 JJ JJ ^ J3 ^J Xi ^3 -u Xi — X X X) X ^ o h CM in o O •-' in o VO 1-H CO ^, r^ co 01 X CM CM CO CO ■<fr Tf VO »>. OV in S^ CM >^ <U 4 £ o .2 Of CM ■* 00 CM -+ VO X o o □ o o 5 K ja ■ u. CM CM CO ^~ m »>. O Q K